1. Field of the Disclosure
The present disclosure relates to a control device of a lock-up clutch.
2. Description of the Related Art
A control device of a lock-up clutch which executes flex start control in which the lock-up clutch is slip-engaged when a vehicle starts is conventionally known in the vehicle provided with the lock-up clutch capable of directly connecting input and output members of a fluid-type power transmitting device forming a part of a power transmission path between an engine and a drive wheel and a linear solenoid valve which controls an engagement hydraulic pressure which allows the lock-up clutch to perform engaging operation. Such control device of the lock-up clutch includes one which improves responsiveness of the lock-up clutch to the flex start control by increasing the engagement hydraulic pressure of the lock-up clutch before the flex start control starts (refer to Japanese Patent Application Laid-open No. 2011-202776).
However, the conventional control device of the lock-up clutch increases the engagement hydraulic pressure of the lock-up clutch without consideration of a state of the fluid-type power transmitting device before the flex start control starts. Therefore, according to the conventional lock-up clutch control device, a blow-up amount of an engine speed might increase due to an insufficient slip-engagement amount of the lock-up clutch and torque shock might occur due to rapid transmission of output torque of the engine with delay when the state of the fluid-type power transmitting device shifts from a driven state to a driving state after the flex start control starts.
There is a need for a control device of a lock-up clutch capable of inhibiting increase in a blow-up amount of an engine speed and occurrence of torque shock when acceleration control such as a flex start control starts.